Answers

2015-02-27T19:37:57+05:30
Molecular weight of CaCO3 = 40+12+3*16 = 100g
weight of CaCO3 in = 25g 
moles of CaCO3 = weight/molecular weight
           = 25/100
moles of CaCO3 = 0.25 moles
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2015-02-27T20:03:11+05:30
Given mass=25 g Molar mass of CaCO3=[(40×1)+(12×1)+(16×3)] g =40g+12g+48g =100g No. of moles= given mass/molar mass =25g/100g=1/4 mole or 0.25 mole
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